Re: [boost] [serialization] multiple reg problem

From: Robert Ramey (ramey_at_[hidden])
Date: 2006-09-17 14:01:58

Neal Becker wrote:
> I noticed that if I use both BOOST_CLASS_EXPORT and register_type it
> causes
> an error.  Here is an example:
snip ...

>  template<class Archive>
>  void save (Archive & ar, const unsigned int version) const {
>    ar.register_type (static_cast<derived*>(NULL));  //comment/uncomment 
> this line
>    std::cout << b->min << ' ' << b->max << '\n';
>    ar << BOOST_SERIALIZATION_NVP(b);
>  }
>
>  template<class Archive>
>  void load (Archive & ar, const unsigned int version) {
    ar.register_type (static_cast<derived*>(NULL));  //add this line
>    base* b = NULL;
>    ar >> BOOST_SERIALIZATION_NVP(b);
>    std::cout << b->min << ' ' << b->max << '\n';
>  }
>
>  BOOST_SERIALIZATION_SPLIT_MEMBER()
> };
>

> If ar.register_type is there, you get unregistered exception.

registration must occur symetrically in both save and load.

an easier way to guarentee this would be to use:

template<class Archive>
void serialize(Archive & ar, const unsigned int version) {
    ar.register_type (static_cast<derived*>(NULL));
    ar & BOOST_SERIALIZATION_NVP(b);
    std::cout << b->min << ' ' << b->max << '\n';
}

Robert Ramey